sub swapNumber
{
	$_[0] += $_[1];
	$_[1] = $_[0] - $_[1];
	$_[0] -= $_[1];
}

my $d1 = 88;
my $d2 = 99;
print $d1, $d2,"\n";&swapNumber($d1,$d2);
print $d1, $d2;